Breather cap



g like.

United States Patent 3,160,487 BREATHER CAP 'Wiiiis H. Risse, Flossrnoor, Demenie I. ,Tortorieh Chicago, and Raymond G. Bennett, Glympia Fieids, lill.,

assignors Ito Novo industrial Corporation, New York,

NY., a corporation ot New York Filed Feb. 25, 1963, Ser. No. 260,436

.t 3 Claims. (Cl. S5-417) This invention is in the field of breather caps for use on internal combustion engines and ris specifically Con-` Another object is a breather cap which would allow f the crankcase to be pressurized. l

Another object is a breather cap specically constructed to provide the proper ow of air at certain speeds.

Another object is a breather cap specifically constructed for anti-smog conditions. n A

Another object is a closed crankcase Ventilating system. Other objects Will appear from time to time in the ensuing specication andhdrawings in which: l

FIGURE l is a side-view, partly in section, of the breather cap; Y t FIGURE 2 is a Abottom View of FIGURE 1. p FIGURE 3 is a diagrammatic of the engine system. v In FIGURE l, we show a so-called breather cap generally designated 1G which has a cap type formation with a closed top 12 surrounded by closed depending sides 14 and a generally open interior 16 which opens on the bottom. The cap itself is made of an outer cap vor shell 18 which has a cylindrical exterior and is shown With a generally flat top 2G joined integrally to the exf .terior with the sides or exterior terminating at a lower edge 22. The interior of the cap'may be formed by a Y faisais? latented Dec. f 1954 wardly, as at 44, above the at surface 34 so that, in

effect, the bale is rigidly mounted. A central depression 46 may be provided 4in the center of the bale whichy serves as a pilot mounting for a suitable spring 4S;y

shown in this case as a coil spring. The spring, as shown in FIGURE l, is under a certain amount of preload and biases. a valve disk 50 upwardly over the opening or outlet 36.' It willbe noted that we provide a downwardly extending bead 52 around the opening which will function as a seat. Also, it will be noted tha-t the diameter of contact of the spring 43 with the disk is v somewhat lessi than Vthe diameter ofthe valve seat or bead 52.

form itself to the dilerential loading caused by this offset relationship. Y l Y 'Y In FIGURE 3, we have diagrammatically shown an engine 54 in which the crankcase 56 is connected by, a return line 58 to the inlet 60. The return line maybe controlled by a valve structure, designated generally 62, which may be the same or somewhat like conventional Vreturn ow erankcase Ventilatingv valves now on the market, such as shown in U.S.. Patent No. 3,105,477,

shell or interior 24 which turns routwardly at its lower edge, as at26, into a flange which extends out to the lower edge 2?. ofthe exterior or cap. It will be noted that the lower edge of the cap may be crimped around the outstanding edge or ange 26, as at 28.k FiangeY 2 6 may have a plurality of openings, shown in this case as round, as at 39, although these may be slots disposed radially lor circumferentially or'rotherwise. In any4 36within 4the boclyof theV cap opening into theA central Acavity or area may be considered the outlet. We /use the expressioirthat they may"normally be considered v ample, lattention .is directed/to copendingV application the inlet and outletbecause under certain conditions of i reverse flow in normal' breather caps; the j'situation is.

reversed. v

p l. Overthe outlet opening 36, We position'aV non-return l,or check valveV 38 which maytake the form of a bale 'or Vsupport 40, lia'vir1g` three or any number of-legs 42,

v whichfextendupwardly are suitably shapedl to pass Y through openings' in the tlatportioni of the inner shell.

Each suchtleginay be turned loverand extended Aout- Y issued October l, 1963. The return line may be con# nected below ythe air cleaner 64 to the inlet manifoldk as shown, or in any suitable manner, sothat the crank--v casevapors will be e'd back to the inlet.` The ll tube for the crankcase, generally designatedv 66, has theY breather` cap 10 mounted thereon.V The` result is that when the crankcase 56'is pressurized or at a pressurehigher than atmospheric, the breather cap will prevent is particularly true at high engine speeds. manifold vacuum is the least at high enginey speeds, the pressure differential through the return line 5S will otherwise be at a minimum. greater than atmospheric may build up in the crankcase. It is then desirable to prevent crankcase vapors from escaping through the iill tube. i

The use, operation and function of our invention are as follows: f

We provide a 'breather cap land/or closed crankcase Ventilating system. The cap is adapted to bemounted on the lill tube of an internal combustion engine. As is known, the ill tube is used to supply oil to the crankcase of the engine and the tube itself is in direct contact with the crankcase. Such breather caps in the past have been provided with a filtering material so that thenir,

either drawn into or forced out of the crankcase, will be l properly ltered. Where a slight vacuuml exists the, orankcase, air will be drawn in and it is desirable that foreign matters and impurities be removed.

In recent years, the smog problem` in and aroundl a"l number of cities has caused extensive work to be jdone in the development and design of crankcase Ventilating for preventing the gaseousv contents of crankcases from being exhausted directly into the atmosphere. For ex- U.S.v Patent No.' 3, 105,477,issued October 1,11963, in the name of Wilfred W. Lowther. It is very desirable that such systems be closed, meaning that there is noopportunit'y or outlet'whereby the crankcase vapors maye'scapef but must go through-the return tube lto -the air. cleaner or" u carburetor, as the case may be, so that they will again go backjthrough the combustion cycle in the engine. Sincefithevvast majority ofthe crankcase-vapor is made up olif:v

blow-by, this problem is vmost serious athigh speeds'where the pressures developed, in the cylinders are the greatest. When the crankoasepressurized, meaning that the pressure inthe crankcase is greater thanVv atmospheric, the vapors in the crankcase willtend tonow `back .thro-ughvv theiil tube and breater cap.r Underrgcertain circum-.;.1-

This means that thedisk should be of a neo-` prene or simlar type material which will adjustably con` Thus, a pressure somewhat dances, itis very desirable that allv of the crankcase vapors :e forced Ito go back through the return tube and valve nechanism to the intake.

The breather cap shown" in the present application has he advantage that the check valve will' automatically )revent reverse fioW and Will thereby allow" or cause the v :rankcase to be pressurized. This has the advantage that Vith the creation of a positive pressure in the crankcase,v

ively weak so that it overcomes the Weightof the valve iisk but not av great deal more. It is noit desired that he crankcase restrict theV inflow of air when a Vacuum xists in thev crankoase. The present breather cap. with 'ne check valve built directly and integrallyy into it has he advantage that it can be used on after market auto-v aobi'les, meaning carsthat are already on the? road, and t is desired to switch them to a closed crankcase sysem. Also, such a combination breather cap will funcion aswell if not better than units in which thecheck lialve is built integrally intov the cranko'ase or'fill tube and 1 all cases is much easier to change or replace and'serv- While We have shown/the vpreferred form andfsugested several modifications of' our invention, it should e understoodv that suitable additional' modifications, hanges,v substitutions and lalterations may be made Withut departing from the inventions` fundamental theme;

We claim:

1. In a breather cap adapted tov beV mounted on vthe fillv tube of an internall combustion engine, a cap type 'housing having an exterior and yinterior closed at one end and open iat the other and defining a generally annular filter space, inlet openings defined at the lower end of the filter space and an`l outlet opening defined generally in the center of the interior'vvithin` the filter space, and a check valve mounted on the outlet'within the filter space to provide for the free flow of'lair into the fill tube but preventing the reverse flow of crankcase vapors out of the fill tube.

2. In a breather :cap adapted to be mounted on the fill Y tube of an internal combustion engine,'a cap type housing having an exterior andinterior closedf at one end and openx at the other and defining a generally annular filter space, inlet openings defined at the lower end" of the filter space and an outlet opening defined generally in the cen.

ter of the interior, and' a check valve mounted on the outlet to provide for the free ow of air into the fill' tube but preventing the reverseflow of crankcase vapors out of the flli tube,` a bail mounted on the outlet'v opening with a central annular porti-on defining a springI seat disposed away fromthe outlet opening,.a coil 'spring mounted in the seat, a flexible valve` disk biasedvby the spring toward the outlet opening, and an annular seatv formed around the'outlet opening ofa diameter no greater than the outside diameter of the disk.,V t

3. The structure of claim 2 further characterized in that the seat is in the form of a continuousV annular bead projecting towardI the disk. f Y

References Cited in the lfile of.A this patent UNITED STATES PATENTS 1,812,860 faunis- Y July?, 1931 2,186,152# seirz' ".rr Jaaa, 1940 2,359,485 Lowther ocr. 3, 1944 `2,991,775 Schrader July ll, 1961 

1. IN A BREATHER CAP ADAPTED TO BE MOUNTED ON THE FILL TUBE OF AN INTERNAL COMBUSION ENGINE, A CAP TYPE HOUSING HAVING AN EXTERIOR AND INTERIOR CLOSED AT ONE END AND OPEN AT THE OTHER AND DEFINING A GENERALLY ANNULAR FILTER SPACE, INLET OPENINGS DEFINED AT THE LOWER END OF THE FILTER SPACE AND AN OUTLET OPENING DEFINED GENERALLY IN THE CENTER OF THE INTERIOR WITHIN THE FILTER SPACE, AND A CHECK VALVE MOUNTED ON THE OUTLET WITHIN THE FILTER SPACE TO PROVIDE FOR THE FREE FLOW OF AIR INTO THE FILL TUBE BUT PREVENTING THE REVERSE FLOW OF CRANKCASE VAPORS OUT OF THE FILL TUBE. 